1. Field of the Invention
The present invention is directed generally to a method for cutting and shaping members composed of an oxide material using a laser emission.
2. Description of the Related Art
German published application No. 34 37 056 discloses an etching method for manufacturing structures in the surface of a member composed of oxide ceramic and oxide single crystal materials having dielectric properties and the like. In accordance with the known method, the oxide material is impinged with a laser beam in a atmosphere that has a reducing effect on the oxide material at higher temperatures. By directing the laser beam onto the material, elevated temperatures are produced in the material.
For a ceramic oxide material, for example, piezoelectric and/or pyroelectric materials and preferrably for materials composed of lead-/calcium-/barium-/-titanate/-zirconate-/-tantalate and the like, hydrogen is particularly suitable as an atmosphere, or at least as a constituent of the atmosphere, having a reducing effect at higher temperatures.
In particular, the use of an ion laser of argon, of krypton and the like, or the emission from a CO.sub.2 or Nd:YAG laser is well known in such applications. These types, of lasers are extremely high-performance lasers.
Extremely small members of an oxide material, for example, extremely small piezoelectric transducer elements, can be worked with the known method. Such working, in particular, may include cutting the material whereby the width of the cut is in the micrometer range, a relatively great cutting depth can be realized-as well. In comparison to mechanical working and forming, relatively smooth worked surfaces, for example, smooth cut surfaces, are produced with this known working method.
The processing performance achieved by the known method actually leaves no wishes unsatisfied. Compared to purely mechanical working such as sawing, the processing speed of the known method as disclosed in the afore-mentioned German application is significantly higher.
The dielectric, piezoelectric and pyroelectric properties of individual oxide materials are adequately known. However, it has been found that when members of oxide materials are worked with the known method the standard values for these properties are not present as the result of deviations in the values, particularly for materials whose chemical compounds are less stable, for instance, in comparison to the dielectric material aluminum oxide ceramic. Such deviations from the standard values occur to different degrees. It has been found that these deviations are caused by the degree of working of the material. A conclusion drawn therefrom is that the known working methods causes a modification of the material, particularly in the regions of and near the working surfaces, for example, in the regions adjacent the cut surfaces.